You can sing with them by following these words :
Sichi pèndé deugou djoungwai ter
Thoubtèn samp’el norbu eunang bar
Tèndreu nordzine gyatcher kyongwai gueune
Tine-lai kyi, reultso gyai
Dorjé khamsou tèn pai
Tchog-kune djamtsé kyong
Namkeu gawa gyanden oup’ang goung la rék
Beun djong déshi ngathang gyai
Beun djong tcheulkha soum gyi khyeunla dékyi dzogdèn sarpai khyap
Tcheussi kyi pel-yeun dar
Thoubtèn tchog tchour gyaipai dzamling yangpai kyégu shidé pail-la djor
Beun djong tèn dreu guétsen nyi-eu ki
Tashi eunang boum dou trowai si
Nag tchok mune-pai yul-lai gyel gyour tchik
If you don’t undersand tibetan, here’s a translation :
Like a treasure that grants all happiness and kindness wishes,
Buddha’s word rises glittering like a diamond.
You, Protectors, who care for the immense royalty of doctrines and beings
If you could spread your love and compassion
_Like an ocean over the world and universe.
Hoping that the emperor’s head, crowned by humndreds of truth, can reach zenith.
That joy and infinite happiness stretches over the three regions of Tibet,
so that beams the prestigious glory of spiritual and temporal power.
That Buddha’s instruction radiates in ten directions,
and brings all the beings of all the universe
unto happiness and peace.
That the qualities of the Doctrine and from the tibetan people
Shine like a sun with a hundred thousand of rays.
Be their brilliant power victorious of the struggle against dark ignorance.